15. "Vitamin Pills - Miracle or Myth?"

This was the title of a recent Horizon programme (bbc.co.uk/programmes/b0bprdcn) which concluded that vitamin pills were probably a waste of time for the average person in the UK who seems to get enough vitamins from their food. In light of recent similar findings, that was not so surprising, but what was surprising was the results of some meso-analyses that showed that the consumption of vitamin pills might actually be associated with an increase in mortality of between 4% and 12%. So vitamin pill supplements might not just be a waste of money, they might actually increase mortality rates!

However there was another angle that caught my attention because it seemed to resolve the paradox between free radicals and exercise that I've never understood. Free radicals are short lived ionized molecules that are highly reactive in the body because they are chemically unstable, which means that they want to react with other substances, and this can lead to oxidative stress. For years we have been told that free radicals are fundamentally bad and that we should consume antioxidants to neutralize their potentially harmful effects. We obtain anti oxidants naturally through animal and plant foods (e.g. blueberries) or by taking vitamin supplements such as Vitamin A, C, or E. Now here's the paradox that has always bothered me. It has been shown that vigorous cardiovascular exercise produces lots of free radicals in the body, yet cardiovascular exercise has also been shown to improve health outcomes and extend life significantly. How can those two seemingly incompatible statements be reconciled?

There were some fascinating insights reported on the Horizon programme which suggested that free radicals in the body, far from being a bad thing, may actually be beneficial, and that anti-oxidant vitamin supplements might actually negate the beneficial effects of exercise! As someone who used to take a Vitamin C supplement following vigorous cardio exercise in the belief that it would counteract the harmful free radicals produced by the exercise, I was more than a little disturbed to learn that the advice I had followed was not just a waste of money, but potentially harmful. The clinical trials reported in this programme measured changes in insulin sensitivity following cardio exercise for a group of people who were randomly given antioxidant supplements or not. Exercise is known to improve insulin sensitivity so this provided a repeatable measure of one of the benefits of exercise. Astonishingly, they found that those who were given the antioxidant supplements showed none of the improvement in insulin sensitivity that the non-supplemented people did. It was as if the antioxidants negated the beneficial effects of the exercise. It was also reported that, as a result of these findings, a number of athletic teams worldwide had removed antioxidant supplements from their training regimes.

If these findings are correct then they overturn what has been the standard thinking for many years that free radicals are harmful and that we need to consume lots of anti oxidants to counteract them. On the contrary the findings suggest that free radicals are actually a natural part of how our bodies function under exercise. For me, this seems to reconcile the fact that exercise produces lots of free radicals yet also improves health and longevity. Wow! Fat is back on the menu and free radicals may actually be beneficial! Is that the sound of another sacred cow hitting the deck? I am sure we have not heard the last of this one.